[Research on methane concentration monitoring system based on electro-optical modulation interference]

Area of Science:

• Optical Physics
• Gas Sensing Technology
• Interferometry

Context:

• Traditional chemical reaction-based methane monitoring methods suffer from low security and poor stability.
• Optical interferometry offers high stability and strong anti-interference capabilities for methane detection.
• Static interference in conventional interferometer systems limits spectral resolution and accuracy.

Purpose:

• To design an electro-optical modulation interference system to enhance methane concentration detection accuracy.
• To improve spectral resolution by increasing the static optical path length scan range using a variable refractive index crystal (LiNbO3).
• To achieve enhanced resolution without altering the interferometer's physical size through phase-modulated signals.

Summary:

• An electro-optical modulation interference system was developed using LiNbO3 for variable refractive index modulation.
• The system utilizes phase-modulated signals to increase the effective optical path length, significantly improving spectral resolution.
• Simulations indicate a near order-of-magnitude increase in resolution compared to same-sized conventional interferometers.
• Experiments using infrared lasers and acousto-optical modulators validated the system's performance in detecting methane gas.

Impact:

• The developed system demonstrates superior accuracy and stability over traditional pyroelectric methods for methane detection.
• This technology is highly suitable for methane concentration monitoring in complex environments, such as mines.
• Advances methane sensing capabilities, enhancing safety and efficiency in industrial applications.